Bruce has turned down Wolves' offer to take charge of the club's battle against relegation because they are only offering the job for the remaining 13 games of the season.
Bruce, out of work since being sacked by Sunderland in November, stunned Wolves boss Steve Morgan and chief executive Jez Moxey by saying a temporary manager would not be able to save the club from the drop.
The club, who sacked Mick McCarthy last Monday, now have to decide whether to return to No 1 target Bruce with the offer of a two-and-a-half-year deal or stick to their original plan of recruiting someone short term.
However ... former West Ham and Charlton boss Alan Curbishley is believed to be open to the 'trial' suggestion.
Wolves had wanted to make an appointment before their next match, against Newcastle, on Saturday.